High-accuracy three-dimensional aspheric mirror measurement with nanoprofiler based on normal vector tracing method

The demand for high-accuracy aspheric optical elements has increased significantly in recent years. The surface shapes of such optical elements must be measured with 1 nm Peak-to-Valley(PV) accuracy; however, it is difficult to achieve 1 nm PV accuracy with conventional methods. In this research, we developed a nanoprofiler based on the normal vector tracing method that can achieve the required accuracy. An aspheric mirror was measured by using the nanoprofiler, and repeatable, sub-nanometer measurements were achieved. Furthermore, we compared our nanoprofiler results with those of a Fizeau interferometer and found that the difference was within the systematic error.     

Flexible sheet with radiophotoluminescence glass beads for remotely monitoring high beta-surface-contamination

A flexible sheet was made with radiophotoluminescence (RPL) glass beads on an experimental basis for visualization of high beta-surface-contamination. A simple RPL observation system for remote contamination monitoring was constructed with a homemade UV floodlight and a commercially available digital camera with supplementary optical lenses and filters. In preliminary experiments, RPL images were well observed with the digital camera of the present system. Their precise RPL intensity was determined after the correction of nonlinear response of the camera. It was expected from experiments that RPL images of beta-surface-contamination could be quantitatively evaluated through calibration, i.e., the conversion of camera images to dose data on the sheet-type glass dosimeter.     

Near‐Infrared‐Controlled,Targeted Hydrophobic Drug‐Delivery System for Synergistic Cancer Therapy

Hydrophobicity has been an obstacle that hinders the use of many anticancer drugs. A critical challenge for cancer therapy concerns the limited availability of effective biocompatible delivery systems for most hydrophobic therapeutic anticancer drugs. In this study, we have developed a targeted near‐infrared (NIR)‐regulated hydrophobic drug‐delivery platform based on gold nanorods incorporated within a mesoporous silica framework (AuMPs). Upon application of NIR light, the photothermal effect of the gold nanorods leads to a rapid rise in the local temperature, thus resulting in the release of the entrapped drug molecules. By integrating chemotherapy and photothermotherapy into one system, we have studied the therapeutic effects of camptothecin‐loaded AuMP‐polyethylene glycol‐folic acid nanocarrier. Results revealed a synergistic effect in vitro and in vivo, which would make it possible to enhance the therapeutic effect of hydrophobic drugs and decrease drug side effects. Studies have shown the feasibility of using this nanocarrier as a targeted and noninvasive remote‐controlled hydrophobic drug‐delivery system with high spatial/temperal resolution. Owing to these advantages, we envision that this NIR‐controlled, targeted drug‐delivery method would promote the development of high‐performance hydrophobic anticancer drug‐delivery system in future clinical applications.     

Wavelength dispersive X-ray fluorescence imaging using a high-sensitivity imaging sensor

A new wavelength-dispersive X-ray fluorescence (WD-XRF) imaging spectrometer equipped with a high-sensitivity imaging sensor was developed in our laboratory. In this instrument, a straight polycapillary optic was applied instead of a Soller slit as well as a 2D imaging X-ray detector instead of X-ray counters, which are used in conventional WD-XRF spectrometers. Therefore, images of elemental distribution were available after a short exposure time. Ni Kα images and Cu Kα images were clearly obtained at corresponding diffraction angles for a short exposure time of 10 s. By optimizing the spectrometer, the time required for imaging is reduced, leading to XRF image movies. It is difficult to distinguish two peaks (Ti Kα (4.508 keV) and Ba Lα (4.465 keV)) due to the poor energy resolution of EDXRS. However, Ti and Ba images could be successfully observed by the WD-XRF imaging spectrometer. The energy resolution of the developed spectrometer was 25 eV at the Ti Kα peak.     

Preparation and characterization of ZrCO/C composite aerogels

Zr-containing organic aerogels were synthesized by ligand substitution reaction of polyzirconoxone and 2, 4-dihydroxybenzoic acid, followed by polymerization with formaldehyde, and then supercritical drying using CO₂. After carbonization and carbothermal reduction under an argon atmosphere, ZrCO/C composite aerogels with controllable zirconium content (47.8–78.6 wt%) were obtained. The carbothermal reduction was substantially completed at 1,500 °C, and the obtained ZrCO/C composite aerogels exhibit low oxygen contents (9.4–6.7 wt%) and high surface areas (589–147 m²/g). Pore morphologies of the ZrCO/C composite aerogels were investigated in detail by nitrogen sorption measurements, scanning electron microscopy and its associated energy-dispersive X-ray microanalysis measurements. The results show that the aerogels are composed of carbon framework and Zr-conglomerations, and the surface area of aerogel is severely affected by its zirconium content. The presence of reductive ZrC crystals can greatly enhance the oxidation resistance ability of amorphous carbon framework and prevent collapse.     

Theoretical investigation on submicron particle penetration through circular tubes inside a porous medium

The analytical infinite series solution of submicron particle transport in a circular tube bounded by a porous wall, such as a pinhole, is determined under the slip velocity boundary condition, and the solution is verified by using the experimental data in the previous studies for the specific cases. The results show that particle penetration rate increases with the increase of the porous parameter, the axial pressure drop, and the pinhole radius, whereas it decreases with increasing the pinhole length. The penetration rate of nano-particles are more sensitive to the variation of these parameters. However, the differences between the penetrations of particles ranging from 0.3 μm to 1 μm are not evident because the diffusion becomes weak gradually in this size range. In addition, a further comparison is performed between the analytical solution and the existing studies, and approximate expressions are presented for accurate calculation of particle penetration rate through pinholes appearing in porous materials including filter devices and masks.     

Site-Specific Detection of Free Radicals in Membranes Using an Amphiphilic Spin Trap

The detection of free radicals and related species has attracted considerable attention in recent years due to their critical roles in physiological and pathological processes. Among the various methods for the detection of free radicals, electron spin resonance coupled with spin-trapping technique has been an effective approach for the characterization and quantification of free radicals due to its high specificity. In this study, we designed and synthesized a novel amphiphilic spin trap, 2-(diethoxyphosphoryl)-2-heptadecanyl-3,4-dihydro-2H-pyrrole-1-oxide (DEPHdPO), from 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide with a long hydrocarbon chain at the C-5 position of the pyrroline ring, providing the amphiphilic character. The free-radical-trapping ability of DEPHdPO was evaluated by capturing hydroxyl radicals (^·OH), superoxide anions (\( {\text{O}}_{2}^{ \cdot - } \)), and carbon-centered free radicals in a model membrane prepared from sodium dodecyl sulfate (SDS). The results indicate that the hydrophobic hydrocarbon chain of DEPHdPO can be inserted into the inner core of SDS micelles, and the hydrophilic nitronyl functional moiety is located on the surface layer. Thus, various free radicals, including ^·OH radicals, \( {\text{O}}_{2}^{ \cdot - } \) anions, and carbon-centered radicals could be site-specifically detected near the membrane surface. Moreover, DEPHdPO could be successfully located on the surface of thylakoid membranes, and the nearby photo-initiated \( {\text{O}}_{2}^{ \cdot - } \) anions could be trapped site-specifically.     

High-resolution transmission electron microscopy study on reversion of Al2CuMg precipitates in Al–Cu–Mg alloys under irradiation

Image deconvolution analyses showed that reversion of S-Al₂CuMg precipitates occurred in an Al–Cu–Mg alloy during high-resolution transmission electron microscopy observations. A fraction of Mg and Cu atoms in the precipitates diffused into Al matrix due to electron beam irradiation at 300 kV, resulting in structural/chemical reversion of the precipitates. The structural reversion of the S-Al₂CuMg precipitates is closely related with irradiation-induced displacement of atoms. The strong attraction between Cu and Mg atoms might assist the sub-threshold displacement of Cu atoms. One transitional structure is determined to be S′′-Al₁₀Cu₃Mg₃, a precursor of S-Al₂CuMg. Two other transitional structures, Al₃CuMg and Al₁₈Cu₅Mg₅ which have the same lattice parameters of a = c = 0.405 nm as that of S′′-Al₁₀Cu₃Mg₃, but different b values, are suggested.     

取向比对椭球气溶胶粒子散射特性的影响

利用T矩阵和离散坐标法研究了取向比对椭球粒子散射特性的影响, 计算了小尺度范围内椭球粒子的散射特征参量, 包括消光效率因子、不对称因子、单次散射反照率、散射相矩阵及双向反射函数(BRDF). 结果表明, 椭球粒子的散射特性与取向比密切相关, 粒子取向比会影响散射参量的振荡频率和振幅, 与球形粒子散射参量的相对差异也呈周期振荡趋势. 研究还发现, 某些特殊粒子尺寸的散射参量与粒子取向比基本无关. 在多次散射条件下, 分析不同取向比粒子群的BRDF随反射角和光学厚度的变化特性. 结果显示: 不同取向比粒子群的BRDF随反射角的变化趋势基本一致, 球形粒子群比非球形粒子群的BRDF曲线波动振幅更大; 球形-非球形粒子的BRDF相对差异随光学厚度和取向比的增大而减小, 随入射角的增大而增大.     

A DFT study of formaldehyde adsorption on functionalized graphene nanoribbons

Density functional theory (DFT) based ab initio calculations were done to monitor the formaldehyde (CHOH) adsorptive behavior on pristine and Ni-decorated graphene sheet. Structural optimization indicates that the formaldehyde molecule is physisorbed on the pristine sheet via partly weak van der Waals attraction having the adsorption energy of about −15.7 kcal/mol. Metal decorated sheet is able to interact with the CHOH molecule, so that single Ni atoms prefer to bind strongly at the bridge site of graphene and each metal atom bound on sheet may adsorb up to four CHOH. The findings also show that the Ni decoration on graphene surface results in some changes in electronic properties of the sheet and its E_g is remained unchanged after adsorption of CHOH molecules. It is noteworthy to say that no bond cleavage was observed for the adsorption of CHOH on Ni-decorated graphene.